In situ FTIR investigation of adsorption properties of sub-micron Cu2O-doped RuO2 sensing electrode of planar potentiometric pH sensor

摘要

In situ Fourier transform infrared spectroscopy (FTIR) was used to study adsorption properties of 20 mol% Cu2O-doped RuO2 sensing electrode (SE) screen-printed on the platinised alumina substrate of the planar electrochemical pH sensor and subsequently sintered at 800 °C. Morphology and properties of developed SEs were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy and FTIR techniques. It was shown that both Cu2O doping and changes in the sintering condition of the SE affected morphology and adsorption spectra of 20 mol% Cu2O-doped RuO2. Fundamental vibration frequencies of ruthenium–oxygen bond at a temperature of 23 °C as well as region above fundamental frequencies for the sub-micron 20 mol% Cu2O-doped RuO2-SE were identified.